Problem 5 Flashcards
Emotion
Refers to a cluster of 3 distinct but interrelated sets of phenomena
a) physiological responses
b) overt behavior
c) conscious feelings
–> induced by an emotional stimulus
–> innate + universal but outward expression may be modified by cultural learning
Arousal/
Fight-or-flight response
Refers to a collection of BODILY REACTIONS that prepare one to face a challenge/threat
–> either by fighting or running away
ex.: blood pressure, increased heart rate
Autonomic nervous system
ANS
Refers to a collection of nerves + structures that send signals to the adrenal glands, which in turn release stress hormones
–> operate without conscious control
Stress hormones
Hormones that turn the fight or flight response on or off
ex.: epinephrine/adrenaline, glucocorticoids
James-Lange theory of emotion
Somatic theory of emotion
States that conscious feelings of emotion occur when the mind senses the physiological responses associated with a certain kind of arousal
–> Physiological responses to stimuli come first, these determine/induce emotions
ex.: making an angry face, will elicit anger
Cannon-Bard theory of emotion
Stimuli simultaneously evoke both emotions + arousal, with neither causing the other
Two factor theory of emotion
States that our conscious emotional feelings depend not only on our biological responses but also on how we INTERPRET the SITUATION
Given that fear is a negative emotion, why do people still want to see horror movies, that induce fear ?
Strong biological responses caused by a terrifying movie are similar to strong biological responses caused by intense joy/sexual pleasure
–> viewers will interpret the movie as pleasurable rather than threatening, due to safe environment
Piloerection
Refers to a fear response in mammals in which body hair stands on end, making the animal look bigger + more threatening than it is
Do physiological responses automatically equate with emotions in humans ?
No they don’t
–> the same physiological response can evoke many different emotions
ex.: When going out for a run, the increased heart rate doesn’t necessarily relate to fear
Do animals show the same emotional responses as humans ?
- Physiological responses seem consistent across mammals
- -> but can’t be sure which exact feelings are elicited - Laughter like vocalizations were recorded
What is the reason for the “freezing response” ?
It is an innate fear response to a threatening situation which helps small animals too avoid predators
–> one can allocate full attention to sensory inputs to help it determine what + where the threat is
Conditioned Escape
Operant conditioning
Refers to an experimental design in which animals learn to make particular responses in order to
a) escape from
b) terminate
aversive stimuli
Conditioned avoidance (Classical + Operant conditioning)
Refers to an experimental design in which animals learn to make particular responses to
a) avoid
b) prevent exposure
to aversive stimuli
Two factor theory of avoidance learning
States that avoidance learning involves an interaction between classical + operant conditioning
–> explains why avoidance behaviors can be persistent
Cognitive expectancies
Belief that animals learn the expected outcomes of responding/not responding and then make a decision to respond/not respond based on a comparison between the two
Learned helplessness
Exposure to an uncontrollable punisher teaches an expectation that responses are ineffectual, which in turn reduces the motivation to attempt new avoidance responses
ex. : prior exposure to an inescapable shock will teach the animal thad they can’t escape any shock
- -> even in operant learning phase
Which effect do emotions have on memory storage + retrieval ?
- Emotional events are more likely to be discussed more often
- -> memories are repeatedly retrieved, rehearsed, strengthened - Strongest memories are associated with strong emotions (positive/negative)
- Strong memories of strong emotional content comes at the cost of weaker memory for surrounding details
Mood congruency of memory
Principle that it is easier to retrieve memories that match our current mood/emotional state
ex.: Depressed people are more likely to recollect sad memories (vicious cycle)
Flashbulb memories
Refers to a memory formed under conditions of extreme emotions that seems especially vivid + long lasting
Can flashbulb memories be trusted ?
Not necessarily,
- They are merely EMs experienced with great vividness + confidence
- Not easy to say whether details are fully correct
- -> can be incomplete or contain inaccurate details
What are usually the causes for the inaccuracy in flashbulb memories ?
- Source monitoring
- False memories
- -> when discussing memories, one might unconsciously fill in little gaps
Amygdala
Lies anterior to the hippocampus and has different separate nuclei with different input + output pathways
Critical in learned emotional responses + in emotional modulation of memory storage + retrieval
Lateral nucleus
Is the primary ENTRY point for sensory information into amygdala
–> contains the direct + indirect pathways which play an important role in responding to fear-evoking stimuli
Central nucleus
- Receives input from other amygdala nuclei
- Projects out of amygdala –> ANS + Motor centers
–> drives the expression of physiological + behavioral responses
ex. arousal, release of stress hormones + freezing, startle
Basolateral nucleus
- Receives input from lateral nucleus
- Projects out of amygdala –>
a) Cortex
b) hippocampus
c) Basal ganglia
–> drives modulation of memory strorage + retrieval
Skin conductance response
SCR
Refers to a tiny but measurable change in the electrical conductivity of the human skin that occurs when people feel arousal
–> mediated by Central nucleus of amygdala
Indirect Pathway of the amygdala
Allows us to terminate the fear response if the stimulus isn’t threatening at all, by providing extra info
= Thalamus –> Cortex –> amygdala
“Slow but accurate”
Direct pathway of the amygdala
Allows us to react quickly in a life + death situation
= Thalamus –> amygdala
“fast and rough”
Optogenetics
Refers to a technique which causes specific cells to become sensitive to light, after which researchers can use light to turn those specific neurons “on” + “off” at will
–> used to manipulate individual neurons projecting to hippocampus + amygdala
What did Optogenetics reveal about the functions of the lateral amygdala ?
As long as the lateral amygdala is active when the US arrives, conditioning will occur
What does the degree of activity of the amygdala reveal about memory storage ?
- Determines whether new info is stored as an EM or SM
- -> emotional arousal rather causes info to be stored as EM - May provide a signal to strengthen the storage of information in declarative memory
- Without its activity info will still be stored, but not as strongly
How does the amygdala influence memory storage ?
By releasing stress hormones
–> activity of the central amygdala
Blood Brain Barrier
Is a membrane that controls the passage of substances from the blood into the CNS, including the brain
–> protects the brain from many chemicals that might otherwise enter + harm
Epinephrine can’t affect the brain directly due to the blood brain barrier.
How does it overcome this obstacle ?
- Epinephrine activates the brain stem nuclei that produce norepinephrine (NE)
- NE is released to Basolateral amygdala
- Outputs travel to hippocampus + cortex
–> amount of NE released, predicts how well we’ll remember
How might the release of norepinephrine into the basolateral amygdala affect EM storage in the hippocampus + cortex ?
- The activated neurons in the Basolateral amygdala project to neurons in hippocampus + cortex
- The rhythmic activation of these neurons facilitates LTP between the coactive neurons
–> this way the Basolateral amygdala facilitates learning in cortex + hippocampus
When individuals return to a place where they experienced intense sadness or fear, they are sometimes struck with a fresh wave of grief/terror.
Why is that ?
Because the pathways of the amygdala to the hippocampus are reciprocal
–> singles from hippocampus that travel back to amygdala where these signals are incorporated into emotional processing
Medial Prefrontal cortex
Allows us to process emotional stimuli in a manner appropriate to the context in which the stimuli occur
–> exerts control on our emotional reactions, by modulating outputs of amygdala
ex. : reaction to seeing a bear is different in zoo or woods
- -> helps people to maintain balance between too little + too much info
Phobia
Is an excessive + irrational fear of an
a) object
b) fear
c) situation
Specific phobia
Fear of particular objects or social situations
ex.: closed spaces, heights, spiders
Agoraphobia
Generalized fear of leaving home or familiar “safe” areas
What is the cause of a panic attack ?
Release of epinephrine in large amounts, triggering the fight or flight response
What causes phobias ?
Classical conditioning
–> but some phobias might be conditioned though social transmission, as not everyone who has a fear evoking experience develops phobia
ex.: tv, stories etc
Systematic desensitization
Extinction
Therapy in which successive approximations of the fear evoking stimulus are presented while the patient learns to remain relaxed
–> used to treat phobias
When can VR-therapy be useful ?
If the desensitization process would be too expensive or dangerous
ex.: fear of flight
Posttraumatic stress disorder
PTSD
Refers to a psychological syndrome that develops after exposure to a horrific event
–> symptoms include reexperiencing the event, avoiding reminders of the trauma, heightened anxiety
What is the cause of PTSD ?
Classical conditioning
–> anything one might associate with the trauma will become the CS, can therefore be triggered by a wide variety of stimuli
Why can’t patients with PTSD simply forget their unwanted memories ?
PTSD reflects reduced ability to use the prefrontal cortex
–> PFC inhibits hippocampal function and controls the recall of unwanted memories
Extinction therapy
Requires the patient to repeatedly imagine + describe the feared situation under the guidance of a therapist
–> used to treat PTSD
When is one more prone to develop PTSD?
- When the hippocampal volume is smaller than average
2. Heightened amygdala activity to negative emotional stimuli
Algae protein channel rhodopsin
Allows influx of positive ions in response to illumination with blue light
- -> “on” switch
- -> depolarizes
Archeal protein halorhodopsin
Allos influx of negatively charged chlorine ions in response to illumination with yellow laugh
- -> “off” switch
- -> hyperpolarizes
Why does blocking the fear center projection impair fear learning + enhance reward learning ?
These neural circuits are interrelated
–> circuits in the Basolateral amygdala are involved in both fear + reward learning
–> one going to NAC or Central amygdala
–> if one pathway is active, activity of the other decreases
Engram
Refers to a specific neural network that stores unique mores in the brain
How did researches provide evidence for the fact that, positive memories can suppress negative memories, with the help of Optogenetics ?
- Placed transgenic mice in an environment that delivered shocks
- -> negative memory - With help of optogenetics, light sensitive protein was inserted into cells of hippocampus
–> light sensitive protein was linked with the hippocampal cells, making these cells light sensitive
- Shining light on these cells will now artificially reactivate the negative memory
- Then placed mice in a new environment that made them feel safe
- When light is now presented, hippocampal cells will acquire a new positive emotional association
